Rotary anvil construction



2 Sheets-Sheet 1 Filed June 1, 1964 HTT'OPNEKS Sept. 27, 1966 L. E. SAUER ROTARY ANVIL CONSTRUCTION 2 Sheets-Sheet 2 Filed June 1, 1964 IN V TOQ: Lou/5 AUER) BVW We HTToRA/E 45 United States Patent 3,274,873 ROTARY ANVIL CONSTRUCTION Louis E. Sauer, St. Louis, Mo., assignor to L. E. Sauer Machine Company, St. Louis, Mo., a corporation of Missouri Filed June 1, 1964, Ser. No. 371,455 6 Claims. (Cl. 83347) The present invention relates generally to the rotary die cutting art, and more particularly to novel anvil construction.

In rotary die cutting, basically there are spaced rolls, one of which supports cutting rules, blades or dies, and the other of which functions as an anvil against which a workpiece, as a corrugated box blank, is cut. In order to make clean cuts, the cutting dies must go through the corrugated box blank and into the anvil. Today, and for some years, the anvil has been covered in whole or in part with resilient material, as rubber, synthetic rubber, plastics including polyurethane, and the like. Obviously, damage to anvil covers by the cutting dies under the aforesaid operating circumstances is substantial. In fact, until recently, resilient anvils or anvil covers have had short lives, often requiring replacement in as few as twenty thousand cutting impacts. Hence, there has long existed the need for anvil construction which Will accept the destructive thrusts of the cutting dies with minimum damage to the former to give longer life to the anvil and reduce loss caused by down-time, which is required when replacement of an anvil cover is required. Several structures have been developed in an effort to solve the foregoing problem, but in applicants experience, none has solved the problem.

Therefore, an object of the present invention is to provide novel anvil construction for rotary die cutting which solves the long-existing problem of short-lived resilient anvil covers.

In brief, the present no-vel anvil construction comprises a base having an annularly grooved periphery and a cover of resilient material, as polyurethane, having ribs received by the grooves or channels. The interengaging grooves and ribs permit relative annular movement of the resilient cover in respect to the base member.

Therefore, another object of the present invention is to provide a novel anvil construction in which a resilient cover is movable annularly relative to and on a 'base member.

Other objects and advantages of the present invention are to provide a novel anvil construction which is longlived, in which the cover can be readily and quickly replaced as required, which reduces down-time to a minimum both in respect to the requirement of replacement and the actual operation of replacement, in which replacement can be accomplished without dismantling of the machine, and which is economical.

The foregoing and other objects and advantages are apparent from the following description taken with the accompanying drawings, in which:

FIGURE 1 is an end elevation of an anvil employed in rotary die cutting incorporating the teachings of the present invention, parts being broken away and in section for illustration of details;

FIGURE 2 is an enlarged, longitudinal, radial crosssectional view taken on substantially the line 2-2 of FIGURE 1;

FIGURE 3 is a top plan view of the anvil base member;

FIGURE 4 is a vertical, transverse cross-sectional view through vertically aligned die-cutting rolls with an anvil of the present invention on the lower roll and a cutting die on the upper roll, a fragment of a paperboard box blank, or the like, illustrated as passing therebetween in die-cutting relation;

FIGURE 5 is an end view of a modified anvil incorporating the principles of the present invention;

FIGURE 6 is an enlarged fragmentary, longitudinal, radial cross-sectional view taken along the anvil of FIG- URE 5, showing two cover members in abutting relation on the anvil base;

FIGURE 7 is a top plan view of the anvil base member;

FIGURE 8 is an enlarged fragmentary, transverse, vertical cross-sectional view taken on substantially the line 8--8 of FIGURE 7;

FIGURE 9 is an enlarged fragmentary, longitudinal, radial cross-sectional view taken on substantially the line 99 of FIGURE 7; and

FIGURE 10 is an enlarged fragmentary, longitudinal, radial cross-sectional view taken on substantially the line 10-10 of FIGURE 7.

Referring to the drawings more particularly by reference numerals, indicates generally an anvil employed in rotary die cutting incorporating the teachings of the present invention (FIGS. 1-4). The anvil 20 includes a base member 22 formed as two halves 24 and 26. Each half 24 and 26 includes annular, peripheral grooves, channels or slots 28 of inverted T cross-section, two being illustrated as formed in the base member 22.

On the base member 22 is .a resilient cover 30 comprising two halves 32 and 34 of polyurethane, or other suitable resilient material. Each cover half 32 and 34 includes internally disposed annular ribs 36 of inverted T cross-section which engage in the channels 28. The cover halves 32 and 34 are mounted on the base member halves 24 and 26, respectively, by sliding engagement of the ribs 36 with the grooves 28. The cover 30 is free to slide annularly on the base member 22. The ribs 36 may be interrupted instead of continuous, and the shown relationship of grooves in the base member 22 and ribs 36 on the cover 30 may be reversed.

The base member halves 24 and 26 are locked together in the position of FIGURES 1 and 4 by a lock structure 38 which may be of any desired construction.

In FIGURE 4, the anvil 20 is illustrated as splined on a lower roll 40. Onto an upper roll 42 is splined a cutting die support 44 on which is mounted a cutting rule or blade retainer 46 which retains a cutting rule or blade 48. The cutting rule 48 is illustrated as penetrating the paperboard 50 and cutting a little into the anvil cover 30. Since the anvil cover 30 is annularly movable relative to the anvil base 22, the cutting or gouging effect of the cutting rule 48 is reduced to a minimum. In fact, anvils constructed in accordance with the principles of the anvil 20 have served continuously in the rotary die cutting of over two and a half million box blanks, each box Iblank taking two cuts, hence, over five million cuts. This is between one hundred and two hundred times the life of resilient anvils heretofore employed.

In FIGURES 5-10, there is shown a modified novel anvil made in accordance with the principles of the present invention. The anvil 55 includes as a base a solid cylinder 57 having spaced annular grooves, channels or slots 59 of inverted T cross-section, and a number of resilient cover members 61 of polyurethane, or the like, including identical halves 63 and 65, each having annular inner ridges 67 of inverted T cross-section.

With particular reference to FIGURES '7-10, it will be noted that each channel 59 is cut away for a small distance at 69 along the shoulders defining the stem of the inverted T. Each shoulder is undercut at 71 and beveled at 73, as is clearly shown in FIGURES 7-10. The undercuts 71 and the bevels 73, in efiect, form a path for mounting a cover half 63 or on the cylinder 57. A leading edge of the cover half 63 is shoved! beneath the undercuts 71 and pushed into position on the cylinder 57, the ridges 67 readily sliding into and along the channels 59. It should be noted that a unitary or integral cover member 61 may be employed instead of the two cover halves 63 and 65, but it has been found quicker and easier to insert successively two halves 63 and 65.

It is, of course, manifest that the anvil cover 61 may be of any desired width and have any desired number of ridges 67. One or more anvil covers 61 may be disposed on the anvil base 57, which may be of any desired length, depending upon the machine employed.

It is manifest that there has been provided novel anvil construction which fulfills the objects and advantages sought therefor.

It is to be understood that the foregoing description and the accompanying drawing have been given by way of illustration and example. It is also to be understood that changes in form of the elements, rearrangement of parts, and substitution of equivalent elements, which will be obvious to those skilled in the art, are contemplated as within the scope of the present invention which is limited only by the claims which follow.

What is claimed is:

1. In combination, an anvil for rotary die cutting, and the like, comprising an annular base member, and an annular unitary cover mounted on said base member for annular movement bodily in respect thereto, said base member and said cover including axially spaced interfitting annular grooves and ridges, said grooves being constructed for substantially tangential mounting therein of said ridges.

2. The combination of claim 1 in which the walls of the grooves are of interrupted construction.

3. In combination, an anvil for rotary die cutting, and the like, comprising an annular base member, an annular unitary cover mounted on said base member for annular movement bodily in respect thereto, and means for maintaini-ng said base member and said cover operatively in said relatively movable relationship, said maintaining means including a plurality of axially spaced means for substantially tangentially mounting said cover on and removing said cover from said base member without removing said base member from its support.

4. In combination, an anvil for rotary die cutting, and the like, comprising an annular base member, an annular cover mounted on said base member for annular movement bodily in respect thereto, said base member and said cover including interfitting annular grooves and ridges, said grooves including means for substantially tangential mounting therein of said ridges, said grooves being of inverted T cross-section, said grooves being cut away at each side at one point providing an opening, undercut portions, and beveled portions to receive said ribs for said substantially tangential mounting.

5. The combination of claim 3 in which said axially spaced means are interfitting annular grooves and ridges.

6. The combination of claim 5 in which each of said base member and annular cover includes two halves.

References Cited by the Examiner UNITED STATES PATENTS 3,119,312 1/1964 Henc 83347 3,162,076 12/1964 Emerson et al 83347 X 3,200,687 8/1965 Paulson 83-346 FOREIGN PATENTS 1,347,752 11/ 1963 France.

WILLIAM S. LAWSON, Primary Examiner.

WILLIAM W. DYER, JR, Examiner.

F. T. YOST, Assistant Examiner. 

1. IN COMBINATION, AN ANVIL FOR ROTARY DIE CUTTING, AND THE LIKE, COMPRISING AN ANNULAR BASE MEMBER, AND AN ANNULAR UNITARY COVER MOUNTED ON SAID BASE MEMBER FOR ANNULAR MOVEMENT BODILY IN RESPECT THERETO, SAID BASE MEMBER AND SAID COVER INCLUDING AXIALLY SPACED INTERFITTING ANNULAR GROOVES AND RIDGES, SAID GROOVES BEING CONSTRUCTED FOR SUBSTANTIALLY TANGENTIAL MOUNTING THEREIN OF SAID RIDGES. 